ow is the keyword aligned with the plaintext in the Vigen$$re cipher?

Question $16$Answer

a$.$

The keyword is randomly placed within the plaintext.

b$.$

The keyword is aligned at the end of the plaintext.

c$.$

The keyword is aligned once at the beginning of the plaintext.

d$.$

The keyword is repeated as many times as necessary to match the length of the plaintext.

e$.$

None of these